Jacob of Nisibis (, Yaʿqôḇ Nṣîḇnāyâ; died c. AD 338), is a Syriac saint. He was the first bishop of Nisibis, spiritual father of the renowned Syriac writer Ephrem the Syrian, and celebrated ascetic. Jacob was appointed bishop, in 308, of the Christian community of Nisibis in Mesopotamia (modern Nusaybin, located near the Turkey/Syria border). Jacob of Nisibis, also known as James of Nisibis and as Jacob of Nusaybin, is recorded as a signatory at the First Council of Nicaea in 325. He was the first Christian to search for the Ark of Noah, which he claimed to find a piece of on a mountain, Cudi Dagi, in a region near Ararat, 70 miles from Nisibis.